The present invention pertains to thermoplastic blends of .alpha.-olefin/hindered vinylidene monomer interpolymers and aromatic polyethers, such as poly(2,6-dimethyl-1,4-phenylene oxide). The blend components and their ratios were selected to provide materials having superior performance or processability or both.
The generic class of materials covered by .alpha.-olefin/hindered vinylidene monomer substantially random interpolymers and including materials such as .alpha.-olefin/vinyl aromatic monomer interpolymers are known in the art and offer a range of material structures and properties which makes them useful for varied applications, such as compatibilizers for blends of polyethylene and polystyrene as described in U.S. Pat. No. 5,460,818, the disclosure of which is incorporated herein by reference.
Although of these interpolymers are of important utilities in their own right, the plastic designers, chemists and engineers are constantly seeking to improve and expand the applicability of these interpolymers. There is a need to provide materials based on .alpha.-olefin/vinylidene aromatic monomer interpolymers with superior performance characteristics, including upper use service temperature, compared to unmodified polymers, which will further expand the utility of this interesting class of materials.
Further, aromatic polyethers, such as poly(2,6-dimethyl-1,4-phenylene oxide, which is more commonly known as polyphenylene ether(PPE), are well-known engineering thermoplastics possessing relatively high softening points. However, these polymer generally suffer from poor impact resistance and poor processability. Although polymer additives such as polystyrene or high impact polystyrene can be used to improve the processing performance of aromatic polyethers, it is often necessary to utilize others polymers such as styrene/butadiene/styrene block copolymers to achieve desirable performance. In contradistinction to known practices, the present invention makes use of the unexpected compatibility of .alpha.-olefin/vinylidene aromatic monomer interpolymers with aromatic polymers such as, for example, polyphenylene ether(PPE) to provide thermoplastic compositions with improved and expanded practical utility.
The present invention pertains to a blend of polymeric materials comprising
(A) from about 1 to about 99 weight percent based on the combined weight of components (A) and (B) of at least one interpolymer produced from polymerizing a monomer mixture comprising:
(1) from about 5 to about 65 mole percent of (a) at least one vinylidene aromatic monomer, or (b) a combination of at least one vinylidene aromatic monomer and at least one hindered aliphatic vinylidene monomer, and PA1 (2) from about 35 to about 95 mole percent of at least one aliphatic .alpha.-olefin having from about 2 to about 20 carbon atoms; and PA1 (1) from about 1 to about 100 weight percent based on the combined weight of components (B1) and (B2) of an aromatic polyether; and PA1 (2) from 0 to about 99 weight percent based on the combined weight of components (B1) and (B2) of
(B) from about 1 to about 99 weight percent based on the combined weight of components (A) and (B) of a composition comprising:
(a) at least one homopolymer of a vinylidene aromatic monomer, or PA2 (b) at least one interpolymer of one or more vinylidene aromatic monomers, or PA2 (c) at least one interpolymer of at least one vinylidene aromatic monomer and at least one hindered aliphatic vinylidene monomers, or PA2 (d) at least one of (B1) or (B2)(a-c) further comprising an impact modifier, or PA2 (e) a combination of any two or more of (B1) and (B2)(a-d),
(c) from 0 to about 50 weight percent of at least one optional impact modifier, and
(D) from 0 to about 50 weight percent of at least one optional processing aid.
When the polymer blend contains from about 50 to about 99 weight percent of the interpolymer component (A), the invention provides for thermoplastic interpolymer compositions having improved thermal performance, while retaining desirable mechanical properties.
When the polymer blend contains from about 1 to about 50 weight percent of the interpolymer component (A), the invention provides for polymer compositions having improved toughness and processability while retaining desirable mechanical properties.
Another aspect of the present invention pertains to such polymer compositions in the form of a film or sheet, or as a component of a multilayered structure resulting from calendering, blowing, casting or extrusion or coextrusion operations.
Another aspect of the present invention pertains to such polymer compositions and their utility in the form of foams, fibers or emulsions.
Another aspect of the present invention pertains to the utilization of such polymer compositions in adhesives, adhesive formulations and adhesive or sealant applications.
Another aspect of the present invention pertains to injection, compression, extruded or blow molded parts prepared from such polymer compositions.